1. Field of the Invention
The present invention relates to a microbicidal/microbistatic composition for industrial use and method of use. More particularly, it relates to a microbicidal/microbistatic composition for industrial use and a method of killing or inhibiting the growth of microorganisms, which can be used for microbicidal/microbistatic treatment of papermaking process water in paper and pulp industry, cooling water or washing water for various industries, heavy oil sludges, cutting oils, textile oils, paints, antifouling coatings, paper coating liquids, latices, sizings or the like.
2. Description of the Prior Art
Slimes are generated in process water of the paper and pulp industry and cooling water of various industries, due to the growth of bacteria and/or fungi and results in such problems as lowering the quality of products and the efficiency of production. Further, in many industrial products, for example heavy oil sludges, cutting oils, textile oils, paints, various latices and sizings, putrefaction and contamination occur due to the growth of bacteria and fungi which reduces their value.
Thus, many microbicidal agents have been used in order to prevent the problems produced by such microorganisms. Formerly, organomercury compounds, chlorinated phenol compounds and the like were used for this purpose. But these compounds generally show strong toxicity to the human body, fish and shellfish, and cause environmental contamination. Therefore, their use has come to be regulated. Recently, relatively low toxicity compounds such as described below have been used generally as microbicidal compounds for industrial use, namely, organonitrogen-sulfur compounds such as methylene bisthiocyanate, 1,2-benzoisothiazoline-3-one and 5-chloro-2-methyl-4-isothiazoline-3-one; organobromine compounds such as 2,2-dibromo-2-nitroethanol, 2,2-dibromo-3-nitrilopropionamide, 1,2-bis(bromoacetoxy)ethane, 1,4-bis(bromoacetoxy)-2-butene and bistribromomethyl sulfone and the like; and organosulfur compounds such as 4,5-dichloro-1,2-dithiol-3-one.
Such known compounds show different microbicidal spectra and effects and are used corresponding to their working objects. For example, 4,5-dichloro-1,2-dithiol-3-one, 2,2-dibromo-2-nitroethanol, 2,2-dibromo-3-nitrilopropionamide, bistribromomethylsulfone and the like exhibit such activity action that their addition even in small amounts remarkably decreases the number of viable bacteria, (which is referred to as "microbicidal action" hereinafter), but they do not inhibit the growth of viable bacteria for a long period of time, (which is referred to as "antimicrobial (microbistatic) action" hereinafter). Further, methylene bisthiocyanate, 1,2-bis (bromoacetoxy)ethane, 1,4-bis(bromoacetoxy)-2-butene and the like have microbistatic action, but are required to be maintained in a high concentration for a long period in order to be effective.
Therefore, the above mentioned ingredients are often used in combination and this can sometimes demonstrate a synergistic effect. But the effective combinations are limited in number. In addition, it is also known that when a composition containing a single ingredient is continuously used, resistant bacteria appear which decreases the effect of the composition.
Further, the temperature of industrial process water or industrial products to be subjected to a microbicidal/microbistatic treatment will vary greatly depending on the season or other factors. For example, the temperature of papermaking process water is about 40.degree. C. in summer but drops to 15.degree. C. or lower in winter. Such a temperature drop is known to be a factor markedly reducing the microbicidal/microbistatic effects of bactericidal compositions.
The purpose of the present invention is to provide a composition which can exhibit effective microbicidal/microbistatic action in small amounts and can maintain its effectiveness even at lower temperatures.
Nitrobromopropane derivatives of the formula (I) as given below are known from the disclosures in Japanese Published Examined patent application No. 16460/1968, EPA No. 36055 and EPA No. 34684 to have microbicidal activity but they are not known to exhibit a synergistic effect in combination with other agent(s) and maintain this effect even at low temperatures.
On the other hand, 2,2-dibromo-3-nitrilopropionamide as disclosed in for example Japanese Published Unexamined patent application No. 91108/1986, is known to have a microbicidal effect by itself and also exert a synergistic effect by its combined use with 4,5-dichloro-1,2-dithiol-3-one. However, the combination use of the above compound and the nitrobromopropane derivatives of the formula (I) is not known.